Seed dispersai by woolly monkeys (Lagothrix lagothricha) at Caparú Biological Station (Colombia): Quantitative description and qualitative analysis

Abstract

Seed dispersai is considered to play a fundamental role in the maintenance of tropical forest structure and diversity. The aim of this study was to determine the role that woolly monkeys play as seed dispersers at the Caparú Biological Station. We followed two woolly monkey groups for 16 months (960 h of observations), determined their diet, and collected and analyzed 1,397 fecal depositions. In 99 % of the analyzed depositions, we found seeds (93,917 seeds) belonging to at least 118 plant species. We estimated that an individual defecates around 15 times per day, and that the woolly monkey population can disperse more than 6,822 seeds day-1 km-2. However, if corrected for sampling efficiency, this value can reach 70,100 seeds day-1 km-2. The vast majority of seeds that woolly monkeys ingest are dispersed whole and undamaged. The average retention time was around 10 h, and the mean dispersal distance was 577 m (range 0-1, 540 m, N = 66). Germination experiments using dispersed seeds show higher (or equal) germination rates and shorter (or equal) latency times for dispersed seeds compared to controls. Our results confirm the important ecological role that woolly monkeys play in tropical forests and also show that this role depends to a great extent on population densities.